B&H Photo Video offers the Linksys AC750 Dual-Band 802.11ac Wireless Range Extender, model no. RE6300, for $39.99 with free shipping. (Amazon and Newegg, among other stores, have it for the same.) That's the lowest total price we could find by $10. It features dual 2.4GHz and 5GHz bands, WPA/WPA2 encryption, Ethernet, and coverage up to 6,500 square feet.